import React, { useEffect, useRef, useState } from 'react';
import { KeyboardAvoidingView, Modal, Platform, Pressable, ScrollView, Text, TextInput, View } from 'react-native';
import Ionicons from '@expo/vector-icons/Ionicons';
import { styles } from '../styles';
import { cn } from '../utils/cn';

export default function BackupModal({
  visible,
  onClose,
  exportJson,
  importJson,
  setImportJson,
  exportFile,
  importFile,
  applyImport,
}) {
  const exportInputRef = useRef(null);
  const [showExportJson, setShowExportJson] = useState(false);
  const [copyState, setCopyState] = useState('idle');

  useEffect(() => {
    if (!visible) return;
    setShowExportJson(false);
    setCopyState('idle');
  }, [visible]);

  useEffect(() => {
    if (copyState !== 'copied') return undefined;
    const timeout = setTimeout(() => setCopyState('idle'), 1400);
    return () => clearTimeout(timeout);
  }, [copyState]);

  async function handleCopyData() {
    if (Platform.OS === 'web' && typeof navigator !== 'undefined' && navigator.clipboard?.writeText) {
      try {
        await navigator.clipboard.writeText(exportJson);
        setCopyState('copied');
        return;
      } catch {
        // fall through to manual copy fallback
      }
    }

    setShowExportJson(true);
    setCopyState('manual');

    if (Platform.OS === 'android') {
      return;
    }

    requestAnimationFrame(() => {
      exportInputRef.current?.focus?.();
      if (exportInputRef.current?.setNativeProps) {
        exportInputRef.current.setNativeProps({
          selection: { start: 0, end: exportJson.length },
        });
      }
    });
  }

  return (
    <Modal visible={visible} animationType="none" transparent>
      <View className={styles.modalBackdrop}>
        <KeyboardAvoidingView behavior={Platform.OS === 'ios' ? 'padding' : undefined} className={styles.modalKeyboardWrap}>
          <View className={styles.modalCard}>
            <View className={styles.sectionHeader}>
              <View className={styles.sectionHeaderLeft}>
                <View className={styles.sectionHeaderIconWrap}>
                  <Ionicons name="cloud-upload-outline" size={16} color="#d4d4d8" />
                </View>
                <Text className={styles.cardTitle}>Backup & Restore</Text>
              </View>
              <Pressable className={styles.secondaryBtnTight} onPress={onClose}>
                <View className={styles.buttonContent}>
                  <Ionicons name="close" size={14} color="#f4f4f5" />
                  <Text className={styles.secondaryBtnText}>Close</Text>
                </View>
              </Pressable>
            </View>

            <ScrollView keyboardShouldPersistTaps="handled" contentContainerStyle={styles.modalScrollContent} showsVerticalScrollIndicator={false}>
              <View className={styles.sectionHeaderLeft}>
                <Ionicons name="download-outline" size={14} color="#d4d4d8" />
                <Text className={styles.cardTitle}>Export JSON</Text>
              </View>
              <Text className={styles.cardMeta}>Use Show JSON or Copy Data.</Text>

              <View className={styles.actionRow}>
                <Pressable className={cn(styles.secondaryBtnTight, styles.flex)} onPress={() => setShowExportJson((prev) => !prev)}>
                  <View className={styles.buttonContent}>
                    <Ionicons name={showExportJson ? 'eye-off-outline' : 'eye-outline'} size={14} color="#f4f4f5" />
                    <Text className={styles.secondaryBtnText}>{showExportJson ? 'Hide JSON' : 'Show JSON'}</Text>
                  </View>
                </Pressable>

                <Pressable className={cn(styles.primaryBtnTight, styles.flex)} onPress={handleCopyData}>
                  <View className={styles.buttonContent}>
                    <Ionicons name={copyState === 'copied' ? 'checkmark-circle-outline' : 'copy-outline'} size={14} color="#ffffff" />
                    <Text className={styles.primaryBtnText}>{copyState === 'copied' ? 'Copied' : 'Copy Data'}</Text>
                  </View>
                </Pressable>
              </View>

              <Pressable className={styles.secondaryBtn} onPress={exportFile}>
                <View className={styles.buttonContent}>
                  <Ionicons name="share-social-outline" size={15} color="#f4f4f5" />
                  <Text className={styles.secondaryBtnText}>Export File</Text>
                </View>
              </Pressable>

              {copyState === 'manual' ? (
                <Text className={styles.cardMeta}>Direct clipboard is unavailable here. JSON is shown for manual copy.</Text>
              ) : null}

              {showExportJson ? (
                Platform.OS === 'android' ? (
                  <View style={styles.exportJsonBlock}>
                    <Text style={styles.exportJsonText} selectable>{exportJson}</Text>
                  </View>
                ) : (
                  <TextInput
                    ref={exportInputRef}
                    style={styles.inputMultiline}
                    multiline
                    value={exportJson}
                    editable={false}
                    selectTextOnFocus
                  />
                )
              ) : null}

              <View className={styles.sectionHeaderLeft}>
                <Ionicons name="cloud-upload-outline" size={14} color="#d4d4d8" />
                <Text className={styles.cardTitle}>Import JSON</Text>
              </View>
              <Text className={styles.cardMeta}>Paste a previous backup. This will replace current data.</Text>
              <Pressable className={styles.secondaryBtn} onPress={importFile}>
                <View className={styles.buttonContent}>
                  <Ionicons name="document-outline" size={15} color="#f4f4f5" />
                  <Text className={styles.secondaryBtnText}>Pick Backup File</Text>
                </View>
              </Pressable>
              <TextInput
                style={styles.inputMultiline}
                multiline
                value={importJson}
                onChangeText={setImportJson}
                placeholder="Paste backup JSON here"
                placeholderTextColor="#71717a"
              />
              <Pressable className={styles.primaryBtn} onPress={applyImport}>
                <View className={styles.buttonContent}>
                  <Ionicons name="sync-outline" size={15} color="#ffffff" />
                  <Text className={styles.primaryBtnText}>Import & Replace</Text>
                </View>
              </Pressable>
            </ScrollView>
          </View>
        </KeyboardAvoidingView>
      </View>
    </Modal>
  );
}